$\left(4x + 2\right)\left(6x - 8\right) = \ ?$
Explanation: $= 4x \cdot \left(6x - 8\right) + 2 \cdot \left(6x - 8\right)$ $= \left( 4x \cdot 6x \right) + \left( 4x \cdot -8 \right) + \left( 2 \cdot 6x \right) + \left( 2 \cdot -8 \right)$ $= 24x^2 + \left( 4x \cdot -8 \right) + \left( 2 \cdot 6x \right) + \left( 2 \cdot -8 \right)$ $= 24x^2 + \left( -32x + 12x \right) + \left( 2 \cdot -8 \right)$ $= 24x^2 - 20x + \left( 2 \cdot -8 \right)$ $= 24x^2 - 20x - 16$